ST. PETERSBURG, Fla. -- Tropicana Field has not been kind to J.A. Happ.

Five years ago, Happ took a line drive directly to his head, hitting him behind his left ear and fracturing his skull. He fell to the ground hard enough that he strained ligaments in his knee, and it would be three months before he returned to the mound.

Happ will start for Toronto in Thursday's series finale, and while he's been back to the Trop nine times since his injury there, he's won only once, in that same 2013 season, in just his third game back from injury.

Happ is off to a solid 8-3 start with a 3.71 ERA, and he's 4-0 in his last five starts, taking a full run off his season ERA along the way. One of his three losses this season came against the Rays, giving up three runs on four hits in 5 2/3 innings in a May 4 loss where he walked more batters (four) than he struck out (three). On Friday against Baltimore, he was especially sharp, throwing seven innings and allowing only two hits and a single unearned run.

And while he's struggled at Tropicana Field, his overall career numbers against the Rays are better, with a 3-4 record and 5.05 ERA -- he has just one win in 10 appearances against Tampa Bay over the last four seasons.

Tampa Bay, trying to push through a rash of injuries to its starting pitching, continues to experiment regularly with "openers," using relievers as part of bullpen days to start about half their games in recent weeks. Nowhere is the Rays' desperation more glaring than with Thursday's starter, Wilmer Font, who is already playing for his third team this season.

Font pitched six games with the Dodgers, then four with the Athletics, and he's now made five appearances with the Rays. He's 0-3 on the season with a 9.59 ERA, but in his five games with Tampa Bay, he's fared much better, with a 3.24 ERA and 0-1 record. In those five games, he's thrown 8 1/3 innings, allowing three earned runs on five hits. In his last outing, also a makeshift start, he lasted into the third inning Friday against Seattle, but gave up two runs on two hits, getting five of his seven outs via strikeout.

Font has actually faced Toronto already this season while with Oakland -- staked with the ninth inning and a 9-0 lead, he gave up a two-run home run to Yangervis Solarte.

The two American League East rivals went into Wednesday's game within a half-game of each other in the standings, still well ahead of last-place Baltimore.

Toronto gets Thursday off before beginning an interleague stretch at home, with three games against the Nationals, then two against the Braves. The Rays, meanwhile, go on the road for the next week, with four games at the Yankees and three at the Astros, then returning home with seven of their next nine again against the Yankees and Astros.